Device for mounting a tyre on a vehicle rim

ABSTRACT

The invention concerns a device for mounting a tyre on a vehicle rim, said device comprising first means ( 1 ) designed to receive the rim and place it in position for mounting the tyre, an arm ( 2 ) whereof the first end is provided with a head for mounting ( 4 ) the tyre on the rim, said head ( 4 ) being arranged rotatable about is axis of symmetry, second means ( 3   a,    3   b,    3   c,    3   d ) connected to the second end of the arm ( 2 ) and designed to impart to said arm ( 2 ) a rotational movement about the axis of symmetry of the rim in position for mounting the tyre. The arm ( 2 ) is inclined on the axis of symmetry of the rim in the position for mounting the tyre at an acute angle, the first end of said arm ( 2 ) being thus furthest from the axis of symmetry of the rim in the position for mounting the tyre. Thus, the movement of the arm ( 2 ) will not be obstructed by the skew position of the tyre on the rim when it reaches the device.

The present invention relates to a device for mounting a tire on avehicle rim. Such a device comprises a first means designed to receivethe rim and place it in the tire mounting position, an arm, a first endof which is equipped with a head for mounting the tire on the rim, saidhead being arranged so as to rotate on said arm, and a second meansconnected to the second end of the arm and designed to transmit to saidarm a movement of revolution about the axis of symmetry of the rim inthe tire mounting position.

Each sidewall of a tire comprises, on its edge inside said tire, agenerally circular bead, comprising a cable that is often made of metaland is designed to be mounted on a corresponding flange or seat presenton the inner periphery of each flank of a rim. The diameter of the beadin question is usually slightly smaller than that of the rim so that thebead has to be forced onto the corresponding flange of the rim, so as toensure that the tire is held in place as the wheel comprising said tiremounted on its rim travels along a road. The mounting head of a devicefor mounting a tire on its rim carries out this function of forcing thebead of each sidewall of the tire onto the flange of the correspondingrim. This head may consist of a fixed or mobile element, usuallyarranged at one end of a mounting arm of a device for mounting a tire ona vehicle rim and having a shape suitable for the forcing in question.

A device for mounting a tire on its rim according to the prior art isknown from EP482701. Said document describes a device intended inparticular for mounting a tire on a vehicle rim and for dismounting thistire from its rim, in which the arm bearing the mounting head is fixedand the means designed to receive the rim and place it in the mountingposition can rotate. According to said document, the arm bearing themounting head is arranged vertically, its axis being parallel to that ofthe rim in the tire mounting position.

Within the context of an industrial line for first mounting tires ontheir rims, the latter are brought to the mounting device by a transportmeans, for example a conveyor. During this transport, the tirecorresponding to each rim is placed at an angle on the latter, so thatits sidewalls are oblique with respect to the conveying plane of the rimand so that a portion of the tire is closest to the conveyor whereas thediametrically opposite portion is furthest away from it. A tire arrivingin this position at the mounting device may disrupt the rotationalmovement of a vertical arm provided with the mounting head about theaxis of symmetry of the rim, thus disrupting mounting of this tire onsaid rim.

The invention solves this problem by proposing a device for mounting atire on a vehicle rim, in which said arm is inclined at an acute anglewith respect to the axis of symmetry of the rim in the tire mountingposition, the first end of the arm thus being furthest away from theaxis of symmetry of the rim in the tire mounting position.

By virtue of this particular configuration of the arm of the deviceaccording to the invention, the latter describes a frustoconicalrevolution surface during its movement for mounting the tire on its rim,the base of this surface being formed by the curve described by themounting head during this movement. By contrast, the vertical arm of adevice according to the prior art describes a cylindrical revolutionsurface of the same base. Consequently, the movement of the arm of thedevice according to the invention will not be obstructed by the angledposition of the tire on the rim when it arrives at said device undercircumstances where it would be obstructed with a vertical arm accordingto the prior art. Moreover; the inclined position of the arm makes itpossible to position the bead of the sidewall of the tire that isclosest to the conveyor on the corresponding flange or seat of the rimwithout the bead of the sidewall of the tire that is furthest away fromthe conveyor disrupting this positioning and while preventing thislatter bead from being itself positioned on the corresponding flange orseat of the rim at an inopportune moment, during positioning of the beadthat is closest to the conveyor.

Preferred embodiments of the invention are described in the dependentclaims.

The invention will now be described in more detail and by way ofexample, without limiting the scope thereof and with reference to theappended figures, in which:

FIG. 1 a shows a side view of a device according to the invention;

FIG. 1 b shows a front view of the arm of the device shown in FIG. 1 a,equipped with its head for mounting the tire;

FIG. 2 a shows a side view of a first means designed to receive a rimand to place it in the tire mounting position in a device according tothe invention;

FIG. 2 b shows a plan view of the first means shown in FIG. 2 a;

FIG. 2 c shows an exploded perspective view of a portion of the firstmeans shown in FIGS. 2 a and 2 b.

FIG. 1 a shows a device for mounting a tire on a vehicle rim accordingto the invention, this device comprising a first means 1 designed toreceive the rim brought to the device by a conveyor (not shown) andplace it in the tire mounting position. This first means is illustratedin more detail in FIGS. 2 a to 2 c. The device moreover comprises an arm2, a first end of which is equipped with a head 4 for mounting the tire.The second end of the arm 2 is connected to a second means 3 a, 3 b, 3c, 3 d designed to transmit to the arm 2 a movement of revolution aboutthe axis of symmetry of the rim when it is in the tire mounting positionon the first means 1. The second means 3 a, 3 b, 3 c, 3 d comprises aplatform 3 a to which the second end of the arm 2 is connected, a motor3 b designed to drive the arm 2 in said movement of revolution, thisdriving being carried out via a rotation spindle 3 c that connects themotor 3 b to the platform 3 a via an element 3 d for reducing the speedof the motor 3 b and for converting its movement into a rotary movementof the spindle 3 c. Optionally, the motor 3 b may be in directengagement on the spindle 3 c. The arm 2 is inclined at an acute angleof about 14° with respect to the axis of symmetry of the rim in the tiremounting position, so that the first end of the arm 2 is further awayfrom the axis of symmetry of the rim in the tire mounting position thanthe first end of said arm 2. In this way, the movement of this arm 2during mounting of a tire on its rim is not obstructed by the angledposition of the tire on said rim when the latter is brought to thedevice by a conveyor (not shown). The device according to the inventionalso comprises a third means 5 designed to displace the arm 2orthogonally with respect to the axis of symmetry of the rim in the tiremounting position. This third means may comprise a hydraulic ram or anyalternative means which performs the same function. By acting on thethird means 5, it is possible to continuously adjust the position of themounting head 4 and in particular to adjust the distance separating itfrom the abovementioned axis of symmetry, so as to allow the device toadapt to the mounting of tires on rims of various diameters of up to 24inches or even more, it being possible for this device to be used on anycommercial rim size by adapting the diameter of rotational travel of thehead 4 to that of the rim on which a tire is to be mounted.Alternatively, the third means 5 also makes it possible to vary thedistance of the head 4 relative to the axis of symmetry of the rim inthe tire mounting position during the movement of revolution of saidhead 4 about said axis, so that the head 4 describes a revolution curvethat is not circular but rather is for example elliptical or ovoid, soas to adapt to the mounting of tires on all types of rim, evennon-circular rims, and to mount a bead of a tire on a flange or seat ofits rim without any risk of damaging a surface of this bead and inparticular the surface covered with fabric that it has generally on theside of this bead within the tire. The device is moreover provided witha fourth means 6 designed to displace the arm 2 parallel to the axis ofsymmetry of the rim in the tire mounting position. This fourth means maycomprise a hydraulic ram or any other alternative means that performsthe same function. The fourth means 6 can displace a plate 7 providedwith sliding cylinders 9 designed to slide along uprights 8 that areessentially parallel to the axis of symmetry of the rim in the tiremounting position. The plate 7 bears the assembly consisting of the arm2 and the second 3 a-3 d and third 5 means. It is thus possible tocontinuously adjust the height of the head 4 for mounting a tire on itsrim as a function of the width of the latter. Such a displacement alsomakes it possible for said head 4 to mount a first peripheral bead of afirst sidewall of the tire on a corresponding first peripheral flange orseat of a rim and then to be displaced vertically upward or downward soas to mount the second peripheral bead of the second sidewall of thetire in question on the second peripheral flange or seat of said rim.The arm 2 is provided with a fifth means 10, which may comprise a rollerthat can turn about its axis that is essentially parallel to the arm 2,said fifth means being designed to orient at a given angle a bead of thetire that is to be mounted on its rim, so that on the one hand this beaddoes not remain attached to the mounting head 4 and on the other handthe stretching of the cable within the bead during mounting of the tireon its rim is reduced to a minimum. This prevents the tire cable inquestion from breaking. The mounting head 4 essentially has the shape ofa truncated cone or a truncated hemisphere, the axis of symmetry ofwhich is inclined, by an angle of about 62°, with respect to the axis ofsymmetry of the rim in the tire mounting position, the base of said headthen being inclined by an angle of about 28° with respect to this axisof symmetry. The device according to the invention, by virtue of thevarious adjustments of the mounting head 4 that it allows, is extremelyversatile and makes it possible to process all types of rim and tirewithin very short periods, both for mounting a tire on a rim and forpassing from one rim and/or tire format to another.

The device according to the invention moreover also comprises aprogrammable control unit (not shown) designed to receive informationrelating to the type of rim, the type of tire and the type of valve ofsaid tire that is to be mounted on said rim, and to control in returnthe position of the arm 2 and of the head 4 during mounting of the tireon the rim.

FIGS. 2 a-2 c show in detail a first means of a device according to theinvention, designed to receive a rim and place it in the position formounting a tire on this rim. This first means comprises a first and asecond parallel notched spindle 11 a, 11 b, respectively, which arecoupled by a gearwheel 12 and arranged below the plane for receivingsaid rim in the mounting device. The spindles 11 a, 11 b are designed sothat the displacement of one in one direction causes the displacement ofthe other in the opposite direction. Each of said spindles 11 a and 11 bis connected via a transmission block, 13 a and 13 b respectively, to apair of clamps 14 a and 14 b, respectively, each block 13 a, 13 b isconnected to sixth means, 15 a, 15 b respectively, which may comprise ahydraulic ram or any other means that can perform the same function,designed to apply a force to the block in question in the direction ofthe spindle 11 a, 11 b which said block connects to the pair of clampsin question and in opposite directions, so as to displace each clamp, inthe direction of the spindle to which it is connected, between aposition of engagement with a peripheral edge of the rim by each clampand for mounting the tire and a position of disengagement from saidperipheral edge by each clamp once said tire has been mounted. In thisway, once the rim has been received in the device, it is placed in thetire mounting position by the pairs of clamps 14 a and 14 b which aredisplaced toward one another by the blocks which bear them, in thedirection of the spindle to which they are connected. When they comeinto contact with the rim, the pairs of clamps 14 a, 14 b transmit tosaid rim the force applied by the means 15 a, 15 b to the blocks 13 aand 13 b, and block it in its tire mounting position, without this forcebeing transmitted via the gearwheel 12, also referred to as thesynchronization pinion. Once mounting has been carried out, thedirection of the forces applied by the means 15 a, 15 b to the blocks 13a, 13 b is reversed and the pairs of clamps 14 a and 14 b are moved awayfrom one another so as to release the rim. The first means designed toreceive a rim and place it in the tire mounting position likewisecomprises a hub 16 which can be retracted below the plane for receivingthe rim, designed to engage a central orifice of said rim when it isreleased from its tire mounting position once said tire has been mountedon said rim. Thus, the rim is held in place when the pairs of clamps 14a and 14 b are disengaged. The first means also comprises two pairs ofpins, 17 a and 17 b respectively, which can be retracted below the planefor receiving the rim and are designed to contact the inner edge of therim with a view to holding it in place when it is released from its tiremounting position once said tire has been mounted on said rim. Themovement of each pair of pins, 17 a and 17 b respectively, iscoordinated with that of a corresponding pair of clamps, 14 a, 14 brespectively, a peripheral edge of the rim present in the device beingarranged between a pair of pins and the corresponding pair of clampsonce a tire has been mounted on its rim by the device. In this way, whena pair of clamps 14 a, 14 b approaches a peripheral edge of the rim, thecorresponding pair of pins 17 a, 17 b moves apart and vice versa. Thus,the rim is held in place by the pins in question once the tire has beenmounted and the pairs of clamps 14 a and 14 b move away from the rim,even if the latter does not comprise a central orifice that can receivethe hub 16.

1. A device for mounting a tire on a vehicle rim, said device comprisinga first means (1) designed to receive the rim and place it in the tiremounting position, an arm (2), a first end of which is equipped with ahead (4) for mounting the tire on the rim, said head (4) being arrangedso as to rotate about its axis of symmetry, a second means (3 a, 3 b, 3c, 3 d) connected to the second end of the arm (2) and designed totransmit to said arm a movement of revolution about the axis of symmetryof the rim in the tire mounting position, characterized in that said arm(2) is inclined at an acute angle with respect to the axis of symmetryof the rim in the tire mounting position, the first end of the arm (2)thus being furthest away from the axis of symmetry of the rim in thetire mounting position.
 2. The device as claimed in claim 1,characterized in that it comprises a third means (5) designed todisplace the arm (2) orthogonally with respect to the axis of symmetryof the rim in the tire mounting position, and a fourth means (6)designed to displace the arm (2) parallel to the axis of symmetry of therim in the tire mounting position.
 3. The device as claimed in claim 2,characterized in that it comprises a fifth means (10) designed to orientat a given angle a bead of the tire that is to be mounted on its rim. 4.The device as claimed in claim 1, characterized in that the axis ofrotation of the head (4) for mounting the tire is inclined at an acuteangle with respect to the axis of symmetry of the rim in the tiremounting position.
 5. The device as claimed in claim 4, characterized inthat the head (4) for mounting the tire essentially has the shape of atruncated cone.
 6. The device as claimed in claim 4, characterized inthat the head (4) for mounting the tire essentially has the shape of atruncated hemisphere.
 7. The device as claimed in claim 1, characterizedin that it comprises a programmable control unit designed to receiveinformation relating to the type of rim and the type of tire to bemounted, and to control in return the position of the arm (2) duringmounting of the tire on the rim by the device.
 8. The device as claimedin claim 3, characterized in that the first means (1) designed toreceive the rim and place it in the tire mounting position comprises afirst (11 a) and a second (11 b) notched spindle which are coupled by agearwheel (12) and arranged below the plane for receiving said rim, eachof said spindles (11 a, 11 b) being connected via a transmission block(13 a, 13 b) to at least one clamp (14 a, 14 b), each transmission block(13 a, 13 b) being connected to sixth means (15 a, 15 b) designed toapply a force to said block (13 a, 13 b) in the direction of the spindle(11 a, 11 b) which it connects to each clamp (14 a, 14 b) and inopposite directions, so as to displace each clamp (14 a, 14 b) between aposition of engagement with a peripheral edge of the rim by each clamp(14 a, 14 b) and for mounting the tire and a position of disengagementfrom said peripheral edge by each clamp (14 a, 14 b) once said tire hasbeen mounted on the rim.
 9. The device as claimed in claim 8,characterized in that it comprises a hub (16) designed to engage acentral orifice of said rim when it is released from its tire mountingposition once said tire has been mounted on said rim.
 10. The device asclaimed in claim 8, characterized in that it comprises at least two pins(17 a, 17 b) designed to contact the inner edge of the rim with a viewto holding it in place when it is released from its tire mountingposition once said tire has been mounted on said rim.